an emergent
website design
by
peter jay stein, md, ma
atmosphere
asthenosphere
lithosphere
regolith
biosphere
hydrosphere
This 54 page synopsis of the evolution
of the Earth, the origin and progression of life, and the
emergence of humans as descendants of the hominin lineage, divides the last 4.57 billion years into progressively overlapping, imagistic, time segments, to outline our place in biological existence.
magnetosphere
ionosphere
FOURTEEN
Emergent Animals II:
The March Towards the Veretebrates
adapted from Biology, 10th Edition, 2015, pp. 533, 625
PROKARYOTES
PROTISTS
EUKARYOTE
2200 mya (2.2 bya)
CHOANOFLAGELLATE ANCESTOR
THE FIRST ANIMAL!
(The Animal Kingdom)
unikont
bikont
(clade)
(clade)
(2 flagella)
opisthokont
bilateria
radiata
ctenophors - biradial symmetry
porifera (sponges): not true tissues
cnidaria - jellyfish, corals
placozoa
radial symmetry
2 clades
protostomes
deuterostomes
oral blastopore
spiral embryonic cleavage
branch
branch
lophotrochozoans
ecdysozoans
chordates
anal blastopore
echinoderms
hemichordates
radial embryonic cleavage
triploblastic
molluscs
annelids
platyhelminthes
single posterior flagellum
molting cuticle
hydrostatic, fluid-filled,
pseudo-coelom skeleton
nematodes (roundworms)
arthropods
urochordates
(tunicates)
cephalochordates
(lancelets)
VERTEBRATES
clade
clade
coelomates:
see definition 'coelom', below